A current challenge in biodiversity conservation is to develop effective methods for setting conservation priorities at multiple geographic and spatial scales. Numerous paradigms have been offered for the identification and prioritization of sites for conserving biological diversity at a variety of scales (i.e., global, national, regional, local): e.g., hotspots (Myers 1988; 1990); rarity (Rabinowitz et al. 1986; Master 1991); GAP Analysis (Scott et al. 1987; Edwards et al. 1993; Scott et al. 1993; Edwards and Scott 1994); representativeness (Margules et al. 1988; Pressey and Nicholls 1989; Bedward et al. 1992; Belbin 1993; Margules et al. 1994; Awimbo and Norton 1996; etc.). However, practical application of these these models to guide biodiversity conservation and management activities on the ground (Vane-Wright 1978; Kareiva 1993; Margules and Redhead 1995; Edwards et al. 1996) can be challenging (e.g., Prendergast et al. 1993; Lawton et al. 1994; Williams et al., 1996; Dobson et al. 1997). For example, the theoretical underpinnings of different site selection strategies are often implicit, but not stated, leading to misunderstandings of implementation requirements; or the data available for a given area may be insufficient to apply a particular model. In other cases, the models may be applied inappropriately (e.g., in cases where the spatial distribution or other parameters of the data violate critical assumptions of the models).

Biodiversity conservation efforts worldwide increasingly emphasize a regional or ecoregional framework for biodviersity inventory and monitoring, as well as for the identification and prioritization of potential conservation sites (e.g., Dinerstein et al. 1995; Miller 1996; The Nature Conservancy 1996; Saunier and Meganck 1996). Within this framework, actual conservation investments will be influenced by both the choice of data sets for analysis and the choice of site selection strategies (e.g., heuristic vs. optimization; representativeness vs. rarity; complementarity vs. redundancy, etc.). Therefore, we propose to synthesize several existing large regional spatial datasets (for the Intermountain Semidesert ecoregion of the western U.S., encompassing parts of Washington, Oregon, Idaho, Nevada, California, Utah, Wyoming and Montana) (Bailey 1994) as a means of exploring a set of questions which will inform both theoretical and practical aspects of biodiversity conservation.

Project extension: With this proposal we seek a second year of support (beginning in July, 1998) to continue and expand the activities of our NCEAS working group (for a description of the project and summary of results see http://www.nceas.ucsb.edu/projects/2002). Our research aims to enhance the theoretical framework for biodiversity conservation planning, and to develop a novel computer-based approach to the design of nature reserve networks that integrates traditional optimization and heuristic models for reserve siting (based on a representation paradigm that emphasizes spatial patterns of species distribution) (e.g., Kirkpatrick 1983; Margules et. al. 1988; Vane-Wrightet. al. 1991; Church et. al. 1996; Davis et. al. 1996; Pressey et. al. 1996) , with dynamic modeling approaches that emphasize population persistence in both space and time (e.g., Lande and Orzack 1988; Tuljapurkar 1989; Dennis et. al. 1991; Fleming et. al.1994; Lindenmayer et. al. 1995; Possingham & Davies 1995; Pulliam & Dunning 1995).Our pilot study during year one has involved the organization and synthesis of several large biodiversity and land use data sets for the Columbia Plateau ecoregion. Our original NCEAS proposal requested funds for an initial period of twelve months, with possibility of a second year of support to extend and expand our analyses and syntheses, contingent on the success and promise of our accomplishments during the first year. This proposal summarizes progress to date, and outlines the research we propose for a second year of NCEAS support (July, 1998 ¿ June, 1999).